Sydney could be in for a royal surprise when the new ANZAC memorial in Hyde Park opens in October.

Minister for Veteran's Affairs told 9NEWS he is aiming to have the $50 million refurbished memorial open by "The Invictus Games", which begins on October 20.

Prince Harry and his wife Meghan Markle have already committed to making the trip to Sydney for the games, which is a competition for wounded soldiers from across the world.

"We are hoping to have it finished by the Invictus Games, and for the centenary of the signing of The Armistice on November 11 this year." Minister Elliott said.

The original memorial was opened in 1934 by the Duke of Gloucester Prince Henry, the son of King George V. Prince Henry went on to become Governor-General of Australia in 1945.

1,701 soil samples have been collected from suburbs, towns and hamlets from all around NSW. They mark the places our servicemen and women enlisted from in World War One.

They will be placed in a wall of remembrance, along with soil samples from 100 foreign battlefields were ANZAC's lost their lives.

"It indicates where people have come from, the land they are fighting from, but also the land they never returned." Director of NSW Veteran's Affairs Caroline Mackaness said.

Cascading waterfalls on the Liverpool St side of the memorial are also almost finished, a key part of the vision of the original architect Bruce Delitt back in 1929. The Great Depression hamstrung the government of the day to fulfil the plans.

The NSW and Commonwealth Government's and City of Sydney Council are funding the project.